Semiconductor die and method of forming Fo-WLCSP vertical interconnect using TSV and TMV

ABSTRACT

A semiconductor device has a TSV wafer and semiconductor die mounted over the TSV wafer. A channel is formed through the TSV wafer. An encapsulant is deposited over the semiconductor die and TSV wafer. Conductive TMV are formed through the encapsulant over the conductive TSV and contact pads of the semiconductor die. The conductive TMV can be formed through the channel. A conductive layer is formed over the encapsulant and electrically connected to the conductive TMV. The conductive TMV are formed during the same manufacturing process. An insulating layer is formed over the encapsulant and conductive layer. A plurality of semiconductor die of the same size or different sizes can be stacked over the TSV wafer. The plurality of semiconductor die can be stacked over opposite sides of the TSV wafer. An internal stacking module can be stacked over the semiconductor die and electrically connected through the conductive TMV.

FIELD OF THE INVENTION

The present invention relates in general to semiconductor devices and,more particularly, to a semiconductor device and method of forming avertical interconnect using TSV and TMV in fan-out wafer level chipscale package (Fo-WLCSP).

BACKGROUND OF THE INVENTION

Semiconductor devices are commonly found in modern electronic products.Semiconductor devices vary in the number and density of electricalcomponents. Discrete semiconductor devices generally contain one type ofelectrical component, e.g., light emitting diode (LED), small signaltransistor, resistor, capacitor, inductor, and power metal oxidesemiconductor field effect transistor (MOSFET). Integrated semiconductordevices typically contain hundreds to millions of electrical components.Examples of integrated semiconductor devices include microcontrollers,microprocessors, charged-coupled devices (CCDs), solar cells, anddigital micro-mirror devices (DMDs).

Semiconductor devices perform a wide range of functions such as signalprocessing, high-speed calculations, transmitting and receivingelectromagnetic signals, controlling electronic devices, transformingsunlight to electricity, and creating visual projections for televisiondisplays. Semiconductor devices are found in the fields ofentertainment, communications, power conversion, networks, computers,and consumer products. Semiconductor devices are also found in militaryapplications, aviation, automotive, industrial controllers, and officeequipment.

Semiconductor devices exploit the electrical properties of semiconductormaterials. The atomic structure of semiconductor material allows itselectrical conductivity to be manipulated by the application of anelectric field or base current or through the process of doping. Dopingintroduces impurities into the semiconductor material to manipulate andcontrol the conductivity of the semiconductor device.

A semiconductor device contains active and passive electricalstructures. Active structures, including bipolar and field effecttransistors, control the flow of electrical current. By varying levelsof doping and application of an electric field or base current, thetransistor either promotes or restricts the flow of electrical current.Passive structures, including resistors, capacitors, and inductors,create a relationship between voltage and current necessary to perform avariety of electrical functions. The passive and active structures areelectrically connected to form circuits, which enable the semiconductordevice to perform high-speed calculations and other useful functions.

Semiconductor devices are generally manufactured using two complexmanufacturing processes, i.e., front-end manufacturing, and back-endmanufacturing, each involving potentially hundreds of steps. Front-endmanufacturing involves the formation of a plurality of die on thesurface of a semiconductor wafer. Each die is typically identical andcontains circuits formed by electrically connecting active and passivecomponents. Back-end manufacturing involves singulating individual diefrom the finished wafer and packaging the die to provide structuralsupport and environmental isolation.

One goal of semiconductor manufacturing is to produce smallersemiconductor devices. Smaller devices typically consume less power,have higher performance, and can be produced more efficiently. Inaddition, smaller semiconductor devices have a smaller footprint, whichis desirable for smaller end products. A smaller die size may beachieved by improvements in the front-end process resulting in die withsmaller, higher density active and passive components. Back-endprocesses may result in semiconductor device packages with a smallerfootprint by improvements in electrical interconnection and packagingmaterials.

Most if not all Fo-WLCSP require a z-direction electrical interconnectstructure for signal routing and package integration. ConventionalFo-WLCSP z-direction electrical interconnect structures exhibit one ormore limitations. In one example, a conventional Fo-WLCSP contains aflipchip semiconductor die and encapsulant formed over the semiconductordie. An interconnect structure is typically formed over thesemiconductor die and encapsulant for z-direction vertical interconnect.The flipchip semiconductor die is electrically connected to theinterconnect structure with bumps. The bump interconnect makes packagestacking difficult to achieve. In addition, the bumps are susceptible todelamination, particularly for applications requiring a fineinterconnect pitch.

Another Fo-WLCSP interconnect structure is shown in U.S. Pat. No.7,528,009 ('009 patent). A portion of the bottom silicon layer isremoved between adjacent semiconductor die. An insulating layer isformed in the removed silicon area. A portion of the insulating layer isremoved and an electrically conductive material is deposited to form arelatively large z-direction electrical interconnect for thesemiconductor die. The large interconnect structure described in the'009 patent increases the pitch of the interconnect and size of thepackage and, which is counter to general miniaturization demands.

SUMMARY OF THE INVENTION

A need exists for a simple and cost effective Fo-WLCSP interconnectstructure for applications requiring a fine interconnect pitch andvertical package integration. Accordingly, in one embodiment, thepresent invention is a method of making a semiconductor devicecomprising the steps of providing a semiconductor wafer having aplurality of conductive TSV formed through the semiconductor wafer,mounting the semiconductor wafer with the TSV to a carrier, cuttingchannels through the semiconductor wafer to provide a plurality of TSVwafer segments, mounting a semiconductor die to each TSV wafer segment,depositing an encapsulant over the semiconductor die and TSV wafersegment, forming a plurality of vias through the encapsulant over theconductive TSV and contact pads of the semiconductor die, depositing anelectrically conductive material in the vias to form conductive TMV,forming a conductive layer over the encapsulant electrically connectedto the conductive TMV, forming an insulating layer over the encapsulantand conductive layer, and singulating the semiconductor device throughthe channels.

In another embodiment, the present invention is a method of making asemiconductor device comprising the steps of providing a semiconductorwafer having a plurality of conductive TSV formed through thesemiconductor wafer, mounting the semiconductor wafer with the TSV to acarrier, cutting a channel through the semiconductor wafer to provide aTSV wafer segment, mounting a semiconductor die to the TSV wafersegment, depositing an encapsulant over the semiconductor die and TSVwafer segment, forming a plurality of conductive TMV through theencapsulant over the conductive TSV and contact pads of thesemiconductor die, forming a conductive layer over the encapsulantelectrically connected to the conductive TMV, and forming an insulatinglayer over the encapsulant and conductive layer.

In another embodiment, the present invention is a method of making asemiconductor device comprising the steps of providing a TSV waferhaving a plurality of conductive TSV formed through the wafer, mountinga semiconductor die to the TSV wafer, depositing an encapsulant over thesemiconductor die and TSV wafer, and forming a plurality of conductiveTMV through the encapsulant over the conductive TSV and contact pads ofthe semiconductor die.

In another embodiment, the present invention is a semiconductor devicecomprising a TSV wafer having a plurality of conductive TSV formedthrough the wafer. A semiconductor die is mounted to the TSV wafer. Anencapsulant is deposited over the semiconductor die and TSV wafer. Aplurality of conductive TMV is formed through the encapsulant over theconductive TSV and contact pads of the semiconductor die.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a PCB with different types of packages mounted to itssurface;

FIGS. 2 a-2 c illustrate further detail of the representativesemiconductor packages mounted to the PCB;

FIGS. 3 a-3 j illustrate a process of forming a vertical interconnectstructure using TSV and TMV in a Fo-WLCSP;

FIG. 4 illustrates the Fo-WLCSP with a TSV and TMV vertical interconnectstructure;

FIG. 5 illustrates stacked Fo-WLCSP each with a TSV and TMV verticalinterconnect structure;

FIG. 6 illustrates another embodiment of stacked Fo-WLCSP each with aTSV and TMV vertical interconnect structure;

FIG. 7 illustrates the Fo-WLCSP with a TMV formed in the encapsulantchannel;

FIG. 8 illustrates tiered stacking of different size Fo-WLCSP each witha TSV and TMV vertical interconnect structure;

FIG. 9 illustrates stacking of same size Fo-WLCSP each with a TSV andTMV vertical interconnect structure;

FIG. 10 illustrates stacking Fo-WLCSP on opposite sides of TSV wafer;and

FIG. 11 illustrates stacking an ISM and Fo-WLCSP with a TSV and TMVvertical interconnect structure.

DETAILED DESCRIPTION OF THE DRAWINGS

The present invention is described in one or more embodiments in thefollowing description with reference to the figures, in which likenumerals represent the same or similar elements. While the invention isdescribed in terms of the best mode for achieving the invention'sobjectives, it will be appreciated by those skilled in the art that itis intended to cover alternatives, modifications, and equivalents as maybe included within the spirit and scope of the invention as defined bythe appended claims and their equivalents as supported by the followingdisclosure and drawings.

Semiconductor devices are generally manufactured using two complexmanufacturing processes: front-end manufacturing and back-endmanufacturing. Front-end manufacturing involves the formation of aplurality of die on the surface of a semiconductor wafer. Each die onthe wafer contains active and passive electrical components, which areelectrically connected to form functional electrical circuits. Activeelectrical components, such as transistors and diodes, have the abilityto control the flow of electrical current. Passive electricalcomponents, such as capacitors, inductors, resistors, and transformers,create a relationship between voltage and current necessary to performelectrical circuit functions.

Passive and active components are formed over the surface of thesemiconductor wafer by a series of process steps including doping,deposition, photolithography, etching, and planarization. Dopingintroduces impurities into the semiconductor material by techniques suchas ion implantation or thermal diffusion. The doping process modifiesthe electrical conductivity of semiconductor material in active devices,transforming the semiconductor material into an insulator, conductor, ordynamically changing the semiconductor material conductivity in responseto an electric field or base current. Transistors contain regions ofvarying types and degrees of doping arranged as necessary to enable thetransistor to promote or restrict the flow of electrical current uponthe application of the electric field or base current.

Active and passive components are formed by layers of materials withdifferent electrical properties. The layers can be formed by a varietyof deposition techniques determined in part by the type of materialbeing deposited. For example, thin film deposition may involve chemicalvapor deposition (CVD), physical vapor deposition (PVD), electrolyticplating, and electroless plating processes. Each layer is generallypatterned to form portions of active components, passive components, orelectrical connections between components.

The layers can be patterned using photolithography, which involves thedeposition of light sensitive material, e.g., photoresist, over thelayer to be patterned. A pattern is transferred from a photomask to thephotoresist using light. The portion of the photoresist patternsubjected to light is removed using a solvent, exposing portions of theunderlying layer to be patterned. The remainder of the photoresist isremoved, leaving behind a patterned layer. Alternatively, some types ofmaterials are patterned by directly depositing the material into theareas or voids formed by a previous deposition/etch process usingtechniques such as electroless and electrolytic plating.

Depositing a thin film of material over an existing pattern canexaggerate the underlying pattern and create a non-uniformly flatsurface. A uniformly flat surface is required to produce smaller andmore densely packed active and passive components. Planarization can beused to remove material from the surface of the wafer and produce auniformly flat surface. Planarization involves polishing the surface ofthe wafer with a polishing pad. An abrasive material and corrosivechemical are added to the surface of the wafer during polishing. Thecombined mechanical action of the abrasive and corrosive action of thechemical removes any irregular topography, resulting in a uniformly flatsurface.

Back-end manufacturing refers to cutting or singulating the finishedwafer into the individual die and then packaging the die for structuralsupport and environmental isolation. To singulate the die, the wafer isscored and broken along non-functional regions of the wafer called sawstreets or scribes. The wafer is singulated using a laser cutting toolor saw blade. After singulation, the individual die are mounted to apackage substrate that includes pins or contact pads for interconnectionwith other system components. Contact pads formed over the semiconductordie are then connected to contact pads within the package. Theelectrical connections can be made with solder bumps, stud bumps,conductive paste, or wirebonds. An encapsulant or other molding materialis deposited over the package to provide physical support and electricalisolation. The finished package is then inserted into an electricalsystem and the functionality of the semiconductor device is madeavailable to the other system components.

FIG. 1 illustrates electronic device 50 having a chip carrier substrateor printed circuit board (PCB) 52 with a plurality of semiconductorpackages mounted on its surface. Electronic device 50 may have one typeof semiconductor package, or multiple types of semiconductor packages,depending on the application. The different types of semiconductorpackages are shown in FIG. 1 for purposes of illustration.

Electronic device 50 may be a stand-alone system that uses thesemiconductor packages to perform one or more electrical functions.Alternatively, electronic device 50 may be a subcomponent of a largersystem. For example, electronic device 50 may be part of a cellularphone, personal digital assistant (PDA), digital video camera (DVC), orother electronic communication device. Alternatively, electronic device50 can be a graphics card, network interface card, or other signalprocessing card that can be inserted into a computer. The semiconductorpackage can include microprocessors, memories, application specificintegrated circuits (ASIC), logic circuits, analog circuits, RFcircuits, discrete devices, or other semiconductor die or electricalcomponents. The miniaturization and the weight reduction are essentialfor these products to be accepted by the market. The distance betweensemiconductor devices must be decreased to achieve higher density.

In FIG. 1, PCB 52 provides a general substrate for structural supportand electrical interconnect of the semiconductor packages mounted on thePCB. Conductive signal traces 54 are formed over a surface or withinlayers of PCB 52 using evaporation, electrolytic plating, electrolessplating, screen printing, or other suitable metal deposition process.Signal traces 54 provide for electrical communication between each ofthe semiconductor packages, mounted components, and other externalsystem components. Traces 54 also provide power and ground connectionsto each of the semiconductor packages.

In some embodiments, a semiconductor device has two packaging levels.First level packaging is a technique for mechanically and electricallyattaching the semiconductor die to an intermediate carrier. Second levelpackaging involves mechanically and electrically attaching theintermediate carrier to the PCB. In other embodiments, a semiconductordevice may only have the first level packaging where the die ismechanically and electrically mounted directly to the PCB.

For the purpose of illustration, several types of first level packaging,including wire bond package 56 and flip chip 58, are shown on PCB 52.Additionally, several types of second level packaging, including ballgrid array (BGA) 60, bump chip carrier (BCC) 62, dual in-line package(DIP) 64, land grid array (LGA) 66, multi-chip module (MCM) 68, quadflat non-leaded package (QFN) 70, and quad flat package 72, are shownmounted on PCB 52. Depending upon the system requirements, anycombination of semiconductor packages, configured with any combinationof first and second level packaging styles, as well as other electroniccomponents, can be connected to PCB 52. In some embodiments, electronicdevice 50 includes a single attached semiconductor package, while otherembodiments call for multiple interconnected packages. By combining oneor more semiconductor packages over a single substrate, manufacturerscan incorporate pre-made components into electronic devices and systems.Because the semiconductor packages include sophisticated functionality,electronic devices can be manufactured using cheaper components and astreamlined manufacturing process. The resulting devices are less likelyto fail and less expensive to manufacture resulting in a lower cost forconsumers.

FIGS. 2 a-2 c show exemplary semiconductor packages. FIG. 2 aillustrates further detail of DIP 64 mounted on PCB 52. Semiconductordie 74 includes an active region containing analog or digital circuitsimplemented as active devices, passive devices, conductive layers, anddielectric layers formed within the die and are electricallyinterconnected according to the electrical design of the die. Forexample, the circuit may include one or more transistors, diodes,inductors, capacitors, resistors, and other circuit elements formedwithin the active region of semiconductor die 74. Contact pads 76 areone or more layers of conductive material, such as aluminum (Al), copper(Cu), tin (Sn), nickel (Ni), gold (Au), or silver (Ag), and areelectrically connected to the circuit elements formed withinsemiconductor die 74. During assembly of DIP 64, semiconductor die 74 ismounted to an intermediate carrier 78 using a gold-silicon eutecticlayer or adhesive material such as thermal epoxy or epoxy resin. Thepackage body includes an insulative packaging material such as polymeror ceramic. Conductor leads 80 and wire bonds 82 provide electricalinterconnect between semiconductor die 74 and PCB 52. Encapsulant 84 isdeposited over the package for environmental protection by preventingmoisture and particles from entering the package and contaminating die74 or wire bonds 82.

FIG. 2 b illustrates further detail of BCC 62 mounted on PCB 52.Semiconductor die 88 is mounted over carrier 90 using an underfill orepoxy-resin adhesive material 92. Wire bonds 94 provide first levelpackaging interconnect between contact pads 96 and 98. Molding compoundor encapsulant 100 is deposited over semiconductor die 88 and wire bonds94 to provide physical support and electrical isolation for the device.Contact pads 102 are formed over a surface of PCB 52 using a suitablemetal deposition process such as electrolytic plating or electrolessplating to prevent oxidation. Contact pads 102 are electricallyconnected to one or more conductive signal traces 54 in PCB 52. Bumps104 are formed between contact pads 98 of BCC 62 and contact pads 102 ofPCB 52.

In FIG. 2 c, semiconductor die 58 is mounted face down to intermediatecarrier 106 with a flip chip style first level packaging. Active region108 of semiconductor die 58 contains analog or digital circuitsimplemented as active devices, passive devices, conductive layers, anddielectric layers formed according to the electrical design of the die.For example, the circuit may include one or more transistors, diodes,inductors, capacitors, resistors, and other circuit elements withinactive region 108. Semiconductor die 58 is electrically and mechanicallyconnected to carrier 106 through bumps 110. p BGA 60 is electrically andmechanically connected to PCB 52 with a BGA style second level packagingusing bumps 112. Semiconductor die 58 is electrically connected toconductive signal traces 54 in PCB 52 through bumps 110, signal lines114, and bumps 112. A molding compound or encapsulant 116 is depositedover semiconductor die 58 and carrier 106 to provide physical supportand electrical isolation for the device. The flip chip semiconductordevice provides a short electrical conduction path from the activedevices on semiconductor die 58 to conduction tracks on PCB 52 in orderto reduce signal propagation distance, lower capacitance, and improveoverall circuit performance. In another embodiment, the semiconductordie 58 can be mechanically and electrically connected directly to PCB 52using flip chip style first level packaging without intermediate carrier106.

FIGS. 3 a-3 j illustrate, in relation to FIGS. 1 and 2 a-2 c, a processof forming a vertical interconnect structure using TSV and TMV in aFo-WLCSP. In FIG. 3 a, a substrate or carrier 120 contains temporary orsacrificial base material such as silicon, polymer, polymer composite,metal, ceramic, glass, glass epoxy, beryllium oxide, or other suitablelow-cost, rigid material for structural support.

A semiconductor wafer 122 contains a base substrate material, such assilicon, germanium, gallium arsenide, indium phosphide, or siliconcarbide, for structural support. A plurality of vias is formed throughsemiconductor wafer 122 using mechanical drilling, laser drilling, ordeep reactive ion etching (DRIE). The vias are filled with Al, Cu, Sn,Ni, Au, Ag, Ti, tungsten (W), poly-silicon, or other suitableelectrically conductive material using electrolytic plating, electrolessplating process, or other suitable metal deposition process to formz-direction conductive through silicon vias (TSV) 124. TSV wafer 122-124is mounted to carrier 120, as shown in FIG. 3 b.

In FIG. 3 c, a channel 126 is cut through semiconductor wafer 122 downto carrier 120 using saw blade or laser cutting tool 127 to create aplurality of TSV wafer portions or segments 128.

In FIG. 3 d, semiconductor die 130 has an active surface 132 containinganalog or digital circuits implemented as active devices, passivedevices, conductive layers, and dielectric layers formed within the dieand electrically interconnected according to the electrical design andfunction of the die. For example, the circuit may include one or moretransistors, diodes, and other circuit elements formed within activesurface 132 to implement analog circuits or digital circuits, such asdigital signal processor (DSP), ASIC, memory, or other signal processingcircuit. Semiconductor die 130 may also contain IPDs, such as inductors,capacitors, and resistors, for RF signal processing. In one embodiment,semiconductor die 130 is a flipchip type semiconductor die.

An electrically conductive layer 134 is formed over active surface 132using PVD, CVD, electrolytic plating, electroless plating process, orother suitable metal deposition process. Conductive layer 134 can be oneor more layers of Al, Cu, Sn, Ni, Au, Ag, or other suitable electricallyconductive material. Conductive layer 134 operates as contact padselectrically connected to the circuits on active surface 132.

Semiconductor die 130 are mounted to TSV wafer segments 128 with dieattach adhesive 136. Semiconductor die 130 each have smaller footprintthan TSV wafer segment 128. Accordingly, TSV 124 a around a perimeter ofwafer segment 128 are outside the footprint of semiconductor die 130 andthe remaining TSV 124 b are disposed under semiconductor die 130.

In FIG. 3 e, an encapsulant or molding compound 140 is deposited overcarrier 120, semiconductor die 130, and TSV wafer segments 128,including into channel 126, using a paste printing, compressive molding,transfer molding, liquid encapsulant molding, vacuum lamination, spincoating, or other suitable applicator. Encapsulant 140 can be polymercomposite material, such as epoxy resin with filler, epoxy acrylate withfiller, or polymer with proper filler. Encapsulant 140 is non-conductiveand environmentally protects the semiconductor device from externalelements and contaminants.

In FIG. 3 f, a plurality of vias 142 is formed through encapsulant 140over TSV 124 a and contact pads 134 using mechanical drilling, laserdrilling, mold chase, or DRIE. The vias 142 are filled with Al, Cu, Sn,Ni, Au, Ag, Ti, tungsten (W), poly-silicon, or other suitableelectrically conductive material using electrolytic plating, electrolessplating process, screen printing, or other suitable metal depositionprocess to form z-direction conductive through mold vias or pillars(TMV) 144, as shown in FIG. 3 g. Conductive TMV 144 a are electricallyconnected to TSV 124 a, and conductive TMV 144 b are electricallyconnected to contact pads 134. The formation of vias 142 and fill withconductive material to form conductive TMV 144 is performed during thesame manufacturing step, which reduces cost in a mass productionenvironment.

In FIG. 3 h, an electrically conductive layer or redistribution layer(RDL) 146 is formed over encapsulant 140 and conductive TMV 144 usingpatterning and screen printing, electrolytic plating, electrolessplating process, or other suitable metal deposition process. Conductivelayer 146 can be one or more layers of Al, Cu, Sn, Ni, Au, Ag, or othersuitable electrically conductive material. Conductive layer 146 iselectrically connected to conductive TMV 144 a and 144 b. Additional RDL146 can be formed over encapsulant 140 in an electrically common orelectrically isolated arrangement depending on the design and functionof semiconductor die 130.

In FIG. 3 i, an insulating or passivation layer 148 is formed overencapsulant 140 and conductive layer 146 by PVD, CVD, printing, spincoating, spray coating, or thermal oxidation. The insulating layer 148can be one or more layers of silicon dioxide (SiO2), silicon nitride(Si3N4), silicon oxynitride (SiON), tantalum pentoxide (Ta2O5), aluminumoxide (Al2O3), or other material having similar insulating andstructural properties. A portion of insulating layer 148 is removed byan etching process to expose conductive layer 146 for bump formation orexternal electrical interconnect.

In FIG. 3 j, carrier 120 is removed by chemical etching, mechanicalpeel-off, CMP, mechanical grinding, thermal bake, laser scanning, wetstripping, UV light, or heat. An electrically conductive bump materialis deposited over the exposed conductive layer 146 using an evaporation,electrolytic plating, electroless plating, ball drop, or screen printingprocess. The bump material can be Al, Sn, Ni, Au, Ag, Pb, Bi, Cu,solder, and combinations thereof, with an optional flux solution. Forexample, the bump material can be eutectic Sn/Pb, high-lead solder, orlead-free solder. The bump material is bonded to conductive layer 146using a suitable attachment or bonding process. In one embodiment, thebump material is reflowed by heating the material above its meltingpoint to form spherical balls or bumps 150. In some applications, bumps150 are reflowed a second time to improve electrical contact toconductive layer 146. An under bumps metallization (UBM) can be formedunder bumps 150. The bumps can also be compression bonded to conductivelayer 146. Bumps 150 represent one type of interconnect structure thatcan be formed over conductive layer 146. The interconnect structure canalso use bond wires, stud bump, micro bump, or other electricalinterconnect.

Semiconductor die 130 and encapsulant 140 is singulated using saw bladeor laser cutting tool 152 to separate the individual semiconductor die130 into Fo-WLCSP 154, as shown in FIG. 4. Semiconductor die 130 iselectrically connected to conductive TMV 144 a and 144 b, conductivelayer 146, and conductive TSV 124 a and 124 b in wafer segment 128. TSV124 a and 124 b can be electrically common or electrically isolateddepending on the design and function of semiconductor die 130. Thecombination of conductive TSV 124 and conductive TMV 144 provide a finepitch z-direction electrical interconnect for semiconductor die 130,which reduces the size of Fo-WLCSP 154. TSV wafer segment 128 has a CTEsimilar to semiconductor die 130 to reduce thermal stress.

Fo-WLCSP 154 is suitable for package-on-package (PoP) orpackage-in-package (PiP) applications. FIG. 5 shows Fo-WLCSP 156configured similar to Fo-WLCSP 154. Fo-WLCSP 156 is stacked overFo-WLCSP 154 and electrically connected with bumps 158 formed betweenconductive layer 146 of Fo-WLCSP 154 and TSV 124 a of Fo-WLCSP 156.Accordingly, semiconductor die 130 in Fo-WLCSP 154 and 156 areelectrically connected through conductive TSV 124, TMV 144, conductivelayer 146, and bumps 158.

FIG. 6 shows an embodiment of Fo-WLCSP 159, similar to FIG. 4, withsemiconductor die 160 mounted over insulating layer 148 with die attachadhesive 162. The stacked semiconductor die 130 and 160 increase thefunctional density of Fo-WLCSP 159. Semiconductor die 160 has an activesurface 164 containing analog or digital circuits implemented as activedevices, passive devices, conductive layers, and dielectric layersformed within the die and electrically interconnected according to theelectrical design and function of the die. For example, the circuit mayinclude one or more transistors, diodes, and other circuit elementsformed within active surface 164 to implement analog circuits or digitalcircuits, such as DSP, ASIC, memory, or other signal processing circuit.Semiconductor die 160 may also contain IPDs, such as inductors,capacitors, and resistors, for RF signal processing. Contact pads 166are formed on active surface 164 and electrically connected to thecircuits on the active surface.

An encapsulant or molding compound 170 is deposited over semiconductordie 160 and insulating layer 148 using a paste printing, compressivemolding, transfer molding, liquid encapsulant molding, vacuumlamination, spin coating, or other suitable applicator. Encapsulant 170can be polymer composite material, such as epoxy resin with filler,epoxy acrylate with filler, or polymer with proper filler. Encapsulant170 is non-conductive and environmentally protects the semiconductordevice from external elements and contaminants.

A plurality of vias is formed through encapsulant 170 down to theexposed conductive layer 146 and contact pads 166 using mechanicaldrilling, laser drilling, mold chase, or DRIE. The vias are filled withAl, Cu, Sn, Ni, Au, Ag, Ti, W, poly-silicon, or other suitableelectrically conductive material using electrolytic plating, electrolessplating process, screen printing, or other suitable metal depositionprocess to form z-direction conductive TMV 172. Conductive TMV 172 a areelectrically connected to conductive layer 146, and conductive TMV 172 bare electrically connected to contact pads 166. The formation of viasand fill with conductive material to form conductive TMV 172 isperformed during the same manufacturing step, which reduces cost in amass production environment.

An electrically conductive layer or RDL 174 is formed over encapsulant170 and conductive TMV 172 using patterning and screen printing,electrolytic plating, electroless plating process, or other suitablemetal deposition process. Conductive layer 174 can be one or more layersof Al, Cu, Sn, Ni, Au, Ag, or other suitable electrically conductivematerial. Conductive layer 174 is electrically connected to conductiveTMV 172 a and 172 b. Additional RDL 174 can be formed over encapsulant170 in an electrically common or electrically isolated arrangementdepending on the design and function of semiconductor die 160.

An insulating or passivation layer 176 is formed over encapsulant 170and conductive layer 174 by PVD, CVD, printing, spin coating, spraycoating, or thermal oxidation. The insulating layer 176 can be one ormore layers of SiO2, Si3N4, SiON, Ta2O5, Al2O3, or other material havingsimilar insulating and structural properties. A portion of insulatinglayer 176 is removed by an etching process to expose conductive layer174 for bump formation or external electrical interconnect.Semiconductor die 130 and 160 are electrically connected throughconductive TMV 144, TMV 172, TSV 124, and conductive layers 146 and 174.

FIG. 7 shows an embodiment of Fo-WLCSP 180, similar to FIG. 4, withconductive TMV 182 formed through encapsulant 140 in channel 126 betweenTSV wafer segments 128. A portion of insulating layer 148 is removed byan etching process to expose conductive TMV 182 for bump formation orexternal electrical interconnect.

FIG. 8 shows an embodiment of Fo-WLCSP 188, continuing from FIG. 3 d,with semiconductor die 190 mounted over semiconductor die 130 with dieattach adhesive 192. Semiconductor die 130 and 190 are different in sizeand therefore stacked in a tiered arrangement. The tiered semiconductordie 130 and 190 increase the functional density of Fo-WLCSP 188.Semiconductor die 190 has an active surface 194 containing analog ordigital circuits implemented as active devices, passive devices,conductive layers, and dielectric layers formed within the die andelectrically interconnected according to the electrical design andfunction of the die. For example, the circuit may include one or moretransistors, diodes, and other circuit elements formed within activesurface 194 to implement analog circuits or digital circuits, such asDSP, ASIC, memory, or other signal processing circuit. Semiconductor die190 may also contain IPDs, such as inductors, capacitors, and resistors,for RF signal processing. Contact pads 196 are formed on active surface194 and electrically connected to the circuits on the active surface.

An encapsulant or molding compound 200 is deposited over semiconductordie 130 and 190 and TSV wafer segment 128 using a paste printing,compressive molding, transfer molding, liquid encapsulant molding,vacuum lamination, spin coating, or other suitable applicator.Encapsulant 200 can be polymer composite material, such as epoxy resinwith filler, epoxy acrylate with filler, or polymer with proper filler.Encapsulant 200 is non-conductive and environmentally protects thesemiconductor device from external elements and contaminants.

A plurality of vias is formed through encapsulant 200 down to contactpads 134 and 196 and TSV 124 a using mechanical drilling, laserdrilling, mold chase, or DRIE. The vias are filled with Al, Cu, Sn, Ni,Au, Ag, Ti, W, poly-silicon, or other suitable electrically conductivematerial using electrolytic plating, electroless plating process, screenprinting, or other suitable metal deposition process to form z-directionconductive TMV 202. Conductive TMV 202 a are electrically connected tocontact pads 196, conductive TMV 202 b are electrically connected tocontact pads 134, and conductive TMV 202 c are electrically connected toTSV 124 a. The formation of vias and fill with conductive material toform conductive TMV 202 is performed during the same manufacturing step,which reduces cost in a mass production environment.

An electrically conductive layer or RDL 204 is formed over encapsulant200 and conductive TMV 202 using patterning and screen printing,electrolytic plating, electroless plating process, or other suitablemetal deposition process. Conductive layer 204 can be one or more layersof Al, Cu, Sn, Ni, Au, Ag, or other suitable electrically conductivematerial. Conductive layer 204 is electrically connected to conductiveTMV 202 a and 202 b. Additional RDL 204 can be formed over encapsulant200 in an electrically common or electrically isolated arrangementdepending on the design and function of semiconductor die 130 and 190.

An insulating or passivation layer 206 is formed over encapsulant 200and conductive layer 204 by PVD, CVD, printing, spin coating, spraycoating, or thermal oxidation. The insulating layer 206 can be one ormore layers of SiO2, Si3N4, SiON, Ta2O5, Al2O3, or other material havingsimilar insulating and structural properties. A portion of insulatinglayer 206 is removed by an etching process to expose conductive layer204 and conductive vias 202 c for bump formation or external electricalinterconnect. Semiconductor die 130 and 190 are electrically connectedthrough conductive TMV 202, TSV 124, and conductive layer 204. Aplurality of bumps 207 is formed over TSV 124 a and 124 b.

FIG. 9 shows an embodiment of Fo-WLCSP 208, continuing from FIG. 3 c,with semiconductor die 210 mounted over TSV wafer segment 128. In oneembodiment, semiconductor die 210 is a flipchip type semiconductor diewith bumps 212 formed between contact pads 216 and TSV 124 b. Contactpads 216 are formed on active surface 214 and electrically connected tothe circuits on the active surface. Semiconductor die 220 is mountedback-to-back with semiconductor die 210 with die attach adhesive 222.Semiconductor die 210 and 220 are similar in size. The stackedsemiconductor die 210 and 220 increase the functional density ofFo-WLCSP 208. Contact pads 226 are formed on active surface 224 ofsemiconductor die 220 and electrically connected to the circuits on theactive surface. Semiconductor die 210 and 220 each have an activesurface containing analog or digital circuits implemented as activedevices, passive devices, conductive layers, and dielectric layersformed within the die and electrically interconnected according to theelectrical design and function of the die. For example, the circuit mayinclude one or more transistors, diodes, and other circuit elementsformed within the active surface to implement analog circuits or digitalcircuits, such as DSP, ASIC, memory, or other signal processing circuit.Semiconductor die 210 and 220 may also contain IPDs, such as inductors,capacitors, and resistors, for RF signal processing.

An encapsulant or molding compound 230 is deposited over semiconductordie 210 and 220 and TSV wafer segment 128 using a paste printing,compressive molding, transfer molding, liquid encapsulant molding,vacuum lamination, spin coating, or other suitable applicator.Encapsulant 230 can be polymer composite material, such as epoxy resinwith filler, epoxy acrylate with filler, or polymer with proper filler.Encapsulant 230 is non-conductive and environmentally protects thesemiconductor device from external elements and contaminants.

A plurality of vias is formed through encapsulant 230 down to contactpads 226 and TSV 124 a using mechanical drilling, laser drilling, moldchase, or DRIE. The vias are filled with Al, Cu, Sn, Ni, Au, Ag, Ti, W,poly-silicon, or other suitable electrically conductive material usingelectrolytic plating, electroless plating process, screen printing, orother suitable metal deposition process to form z-direction conductiveTMV 232. Conductive TMV 232 a are electrically connected to contact pads226 and conductive TMV 232 b are electrically connected to TSV 124 a.The formation of vias and fill with conductive material to formconductive TMV 232 is performed during the same manufacturing step,which reduces cost in a mass production environment.

An electrically conductive layer or RDL 234 is formed over encapsulant230 and conductive TMV 232 using patterning and screen printing,electrolytic plating, electroless plating process, or other suitablemetal deposition process. Conductive layer 234 can be one or more layersof Al, Cu, Sn, Ni, Au, Ag, or other suitable electrically conductivematerial. Conductive layer 234 is electrically connected to conductiveTMV 232 a and 232 b. Additional RDL 234 can be formed over encapsulant230 in an electrically common or electrically isolated arrangementdepending on the design and function of semiconductor die 210 and 220.

An insulating or passivation layer 236 is formed over encapsulant 230and conductive layer 234 by PVD, CVD, printing, spin coating, spraycoating, or thermal oxidation. The insulating layer 236 can be one ormore layers of SiO2, Si3N4, SiON, Ta2O5, Al2O3, or other material havingsimilar insulating and structural properties. A portion of insulatinglayer 236 is removed by an etching process to expose conductive layer234 for bump formation or external electrical interconnect.Semiconductor die 210 and 220 are electrically connected throughconductive TMV 232, TSV 124, and conductive layer 234. A plurality ofbumps 238 is formed over TSV 124 a and 124 b.

FIG. 10 shows an embodiment of Fo-WLCSP 240, continuing from FIG. 3 c,with semiconductor die 242 mounted over surface 244 of TSV wafer segment128 with die attach adhesive layer 246. Contact pads 248 are formed onactive surface 250 of semiconductor die 242 and electrically connectedto the circuits on the active surface. Semiconductor die 252 is mountedover surface 254 of TSV wafer segment 128, opposite surface 244, withdie attach adhesive layer 256. Contact pads 258 are formed on activesurface 260 of semiconductor die 252 and electrically connected to thecircuits on the active surface. The semiconductor die 242 and 252stacked on opposite surfaces 244 and 254 of TSV wafer segment 128increase the functional density of Fo-WLCSP 240. Semiconductor die 242and 252 each have an active surface containing analog or digitalcircuits implemented as active devices, passive devices, conductivelayers, and dielectric layers formed within the die and electricallyinterconnected according to the electrical design and function of thedie. For example, the circuit may include one or more transistors,diodes, and other circuit elements formed within the active surface toimplement analog circuits or digital circuits, such as DSP, ASIC,memory, or other signal processing circuit. Semiconductor die 242 and252 may also contain IPDs, such as inductors, capacitors, and resistors,for RF signal processing.

An encapsulant or molding compound 262 is deposited over semiconductordie 242 and 252 and surfaces 244 and 254 of TSV wafer segment 128 usinga paste printing, compressive molding, transfer molding, liquidencapsulant molding, vacuum lamination, spin coating, or other suitableapplicator. Encapsulant 262 can be polymer composite material, such asepoxy resin with filler, epoxy acrylate with filler, or polymer withproper filler. Encapsulant 262 is non-conductive and environmentallyprotects the semiconductor device from external elements andcontaminants.

A plurality of vias is formed through encapsulant 262 down to contactpads 248 and 258 and both sides of TSV 124 a using mechanical drilling,laser drilling, mold chase, or DRIE. The vias are filled with Al, Cu,Sn, Ni, Au, Ag, Ti, W, poly-silicon, or other suitable electricallyconductive material using electrolytic plating, electroless platingprocess, screen printing, or other suitable metal deposition process toform z-direction conductive TMV 264 and 266. Conductive TMV 264 a areelectrically connected to contact pads 248 and conductive TMV 264 b areelectrically connected to one side of TSV 124 a. Conductive TMV 266 aare electrically connected to contact pads 258 and conductive TMV 266 bare electrically connected to an opposite side of TSV 124 a. Theformation of vias and fill with conductive material to form conductiveTMV 264 and 266 is performed during the same manufacturing step, whichreduces cost in a mass production environment.

An electrically conductive layer or RDL 268 is formed over encapsulant262 and conductive TMV 264 using patterning and screen printing,electrolytic plating, electroless plating process, or other suitablemetal deposition process. Conductive layer 268 can be one or more layersof Al, Cu, Sn, Ni, Au, Ag, or other suitable electrically conductivematerial. Conductive layer 268 is electrically connected to conductiveTMV 264 a and 264 b. Additional RDL 268 can be formed over encapsulant262 in an electrically common or electrically isolated arrangementdepending on the design and function of semiconductor die 242 and 252.

An insulating or passivation layer 270 is formed over encapsulant 262and conductive layer 268 by PVD, CVD, printing, spin coating, spraycoating, or thermal oxidation. The insulating layer 270 can be one ormore layers of SiO2, Si3N4, SiON, Ta2O5, Al2O3, or other material havingsimilar insulating and structural properties. A portion of insulatinglayer 270 is removed by an etching process to expose conductive layer268 for bump formation or external electrical interconnect.Semiconductor die 242 and 252 are electrically connected throughconductive TMV 264, TMV 266, TSV 124, and conductive layer 268. Aplurality of bumps 272 is formed over TMV 266 a and 266 b.

FIG. 11 shows an embodiment of Fo-WLCSP 280, continuing from FIG. 3 c,with semiconductor die 282 mounted over TSV wafer segment 128 with bumps284. In one embodiment, semiconductor die 282 is a flipchip typesemiconductor die with bumps 284 formed between contact pads 288 and TSV124 b. Contact pads 288 are formed on active surface 286 andelectrically connected to the circuits on the active surface. Aninternal stacking module (ISM) 290 is mounted to a back surface ofsemiconductor die 282 with die attach adhesive 291. ISM 290 containssemiconductor die 292 mounted to substrate 294 and electricallyconnected to conductive layers 295 in the substrate with bond wires 296.An encapsulant 298 is deposited over semiconductor die 292, substrate294, and bond wires 296.

An encapsulant or molding compound 300 is deposited over semiconductordie 282, ISM 290, and TSV wafer segment 128 using a paste printing,compressive molding, transfer molding, liquid encapsulant molding,vacuum lamination, spin coating, or other suitable applicator.Encapsulant 300 can be polymer composite material, such as epoxy resinwith filler, epoxy acrylate with filler, or polymer with proper filler.Encapsulant 300 is non-conductive and environmentally protects thesemiconductor device from external elements and contaminants.

A plurality of vias is formed through encapsulant 300 down to TSV 124 ausing mechanical drilling, laser drilling, mold chase, or DRIE. The viasare filled with Al, Cu, Sn, Ni, Au, Ag, Ti, W, poly-silicon, or othersuitable electrically conductive material using electrolytic plating,electroless plating process, screen printing, or other suitable metaldeposition process to form z-direction conductive TMV 302. ConductiveTMV 302 are electrically connected to TSV 124 a. The formation of viasand fill with conductive material to form conductive TMV 302 isperformed during the same manufacturing step, which reduces cost in amass production environment.

An electrically conductive layer or RDL 304 is formed over encapsulant300 and conductive TMV 302 using patterning and screen printing,electrolytic plating, electroless plating process, or other suitablemetal deposition process. Conductive layer 304 can be one or more layersof Al, Cu, Sn, Ni, Au, Ag, or other suitable electrically conductivematerial. Conductive layer 304 is electrically connected to conductiveTMV 302 and substrate 294. Additional RDL 304 can be formed overencapsulant 300 in an electrically common or electrically isolatedarrangement depending on the design and function of semiconductor die282 and ISM 290.

An insulating or passivation layer 306 is formed over encapsulant 300and conductive layer 304 by PVD, CVD, printing, spin coating, spraycoating, or thermal oxidation. The insulating layer 306 can be one ormore layers of SiO2, Si3N4, SiON, Ta2O5, Al2O3, or other material havingsimilar insulating and structural properties. A portion of insulatinglayer 306 is removed by an etching process to expose conductive layer304 for bump formation or external electrical interconnect.Semiconductor die 282 and ISM 290 are electrically connected throughconductive TMV 302, TSV 124, and conductive layer 304. A plurality ofbumps 308 is formed over TSV 124 a and 124 b.

While one or more embodiments of the present invention have beenillustrated in detail, the skilled artisan will appreciate thatmodifications and adaptations to those embodiments may be made withoutdeparting from the scope of the present invention as set forth in thefollowing claims.

What is claimed:
 1. A method of making a semiconductor device,comprising: providing a semiconductor wafer containing semiconductormaterial including a plurality of conductive through silicon vias formedthrough the semiconductor material of the semiconductor wafer; cuttingchannels through the semiconductor wafer to provide a plurality of wafersegments including the conductive through silicon vias; disposing afirst semiconductor die over a wafer segment from the plurality of wafersegments; depositing an encapsulant over the first semiconductor die andwafer segment; forming a first via through the encapsulant to expose aconductive through silicon via of the wafer segment; forming a secondvia through the encapsulant and over a contact pad of the firstsemiconductor die; depositing an electrically conductive material in thefirst and second vias during a same manufacturing step to form a firstconductive through mold via extending through the encapsulant to theexposed conductive through silicon via and a second conductive throughmold via extending through the encapsulant to the first semiconductordie; forming a conductive layer over the encapsulant electricallyconnected to the first and second conductive through mold vias; andforming an insulating layer over the encapsulant and conductive layer.2. The method of claim 1, further including forming a plurality of bumpsover the wafer segment opposite the first semiconductor die.
 3. Themethod of claim 1, further including; stacking a second semiconductordie over the wafer segment; and electrically connecting the first andsecond semiconductor die through the first and second conductive throughmold vias.
 4. The method of claim 3, wherein the first and secondsemiconductor die are different sizes.
 5. The method of claim 1, furtherincluding: stacking a second semiconductor die over the wafer segmentopposite the first semiconductor die; and electrically connecting thefirst and second semiconductor die through the first and secondconductive through mold vias.
 6. The method of claim 1, furtherincluding forming a third conductive through mold via through thechannels.
 7. A method of making a semiconductor device, comprising:providing a semiconductor wafer including a plurality of conductivethrough silicon vias formed through the semiconductor wafer; cutting achannel through the semiconductor wafer to provide a wafer segment;disposing a semiconductor die over the wafer segment; depositing anencapsulant over the semiconductor die and wafer segment; forming afirst conductive through mold via through the encapsulant and over theconductive through silicon vias; forming a second conductive throughmold via through the encapsulant and over a contact pad of thesemiconductor die; forming a conductive layer over the encapsulant andelectrically connected to the first and second conductive through moldvias; forming an insulating layer over the encapsulant and conductivelayer; and forming a third conductive through mold via through thechannel.
 8. The method of claim 7, further including: stacking aplurality of semiconductor die over the wafer segment; and electricallyconnecting the plurality of semiconductor die through the first andsecond conductive through mold vias.
 9. The method of claim 7, furtherincluding: stacking a plurality of semiconductor die over opposite sidesof the wafer segment; and electrically connecting the plurality ofsemiconductor die through the first and second conductive through moldvias.
 10. The method of claim 7, further including: stacking an internalstacking module over the semiconductor die; and electrically connectingthe semiconductor die and internal stacking module through the first andsecond conductive through mold vias.
 11. The method of claim 7, furtherincluding forming a plurality of bumps over the wafer segment oppositethe semiconductor die.
 12. A method of making a semiconductor device,comprising: providing a substrate including a plurality of conductivevias formed through the substrate; disposing a semiconductor die overthe substrate; depositing an encapsulant over the semiconductor die andsubstrate; forming a first via through the encapsulant to expose aconductive via of the substrate; forming a second via through theencapsulant and over a contact pad of the semiconductor die; anddepositing an electrically conductive material in the first via andsecond via to form a first conductive through mold via extending throughthe encapsulant to the exposed conductive via of the substrate and asecond conductive through mold via extending through the encapsulant tothe semiconductor die.
 13. The method of claim 12, further including:forming a conductive layer over the encapsulant and electricallyconnected to the first and second conductive through mold vias; andforming an insulating layer over the encapsulant and conductive layer.14. The method of claim 12, further including: stacking a plurality ofsemiconductor die over the substrate; and electrically connecting theplurality of semiconductor die through the first and second conductivethrough mold vias.
 15. The method of claim 14, wherein the plurality ofsemiconductor die are different sizes.
 16. The method of claim 12,further including: stacking a plurality of semiconductor die overopposite sides of the substrate; and electrically connecting theplurality of semiconductor die through the first and second conductivethrough mold vias.
 17. The method of claim 12, further including:stacking an internal stacking module over the semiconductor die; andelectrically connecting the semiconductor die and internal stackingmodule through the first and second conductive through mold vias. 18.The method of claim 12, further including forming a plurality of bumpsover the substrate opposite the semiconductor die.
 19. A method ofmaking a semiconductor device, comprising: providing a substrateincluding a plurality of conductive vias formed through the substrate;cutting channels through the substrate to provide a plurality ofsubstrate segments including the conductive vias; disposing a firstsemiconductor die over a substrate segment from the plurality ofsubstrate segments; depositing an encapsulant over the firstsemiconductor die and substrate segment; forming a first via through theencapsulant to expose a first conductive via of the substrate segment;forming a second via through the encapsulant and over a contact pad ofthe first semiconductor die; and depositing an electrically conductivematerial in the first via and second via to form a second conductive viaextending through the encapsulant to the exposed first conductive via inthe substrate segment and a third conductive via extending through theencapsulant to the first semiconductor die.
 20. The method of claim 19,further including forming a conductive layer over the encapsulant andelectrically connected to the second and third conductive vias.
 21. Themethod of claim 19, further including: stacking a second semiconductordie over the first semiconductor die; and electrically connecting thefirst and second semiconductor die through the second and thirdconductive vias.
 22. The method of claim 21, wherein the first andsecond semiconductor die are different sizes.
 23. The method of claim19, further including: stacking the first semiconductor die over a firstside of the substrate segment; stacking a second semiconductor die overa second side of the substrate segment; and electrically connecting thefirst and second semiconductor die through the second and thirdconductive vias.